Estuary

• Marine environments begin here

• Areas where freshwater rivers or streams empty into areas of saltwater

• Mobile Bay is an estuary that empties into the Gulf of Mexico, and then to the Atlantic Ocean

What Are Estuaries?• Where the freshwater of a river meets the

salty water of the ocean

• They mix here forming brackish water, which just means a mixture of salt and freshwater.

• You live in the 4th largest estuary system in the US.

Estuaries• Estuaries are one of the most productive

environments on Earth.

• They often contain many wetlands.

• Many marine animals, such as fish & shrimp, begin their lives in estuaries safe from predators. Without the wetlands (in the estuary) these animals would disappear.

Endangered species of the Mobile Bay Estuary

Federally Endangered or Threatened Species:

Mammals:• Alabama beach mouse• West Indian manatee

Birds:• bald eagle• peregrine falcon• piping plover• red-cockaded woodpecker• wood stork

Fish:• Gulf sturgeon

Federally Endangered/Threatened Species:

Reptiles:• Alabama red-bellied turtle• eastern indigo snake• gopher tortoise• loggerhead sea turtle

Insects:• American Burying beetle

Plants:• Alabama canebrake pitcher-plant• American chaffseed• Louisiana quillwort• Mohr's Barbara's buttons

WetlandsWetlands: an area of land where the water

level is near or above the surface of the ground for most of the year.

The United States is losing more than 80,000 acres of wetland habitat annually. That's more than seven football fields each day!

Wetlands

So why are they so important?

• support a variety of animal and plant life

• control flooding by storing flood water

• Filter water ($2,000 worth of water treatment per acre annually X 160,000 acres in Mobile Bay alone!)

• replenish ground water

Two types of wetlands in the US:

a. Marshes: treeless wetland

• find them along the shores of lakes, ponds, rivers, streams, & river deltas

• plants found there depends on the depth of the water & location; grasses, reeds, bulrushes, & wild rice

• animals found there: muskrats, turtles, frogs, and red-winged blackbirds

b. Swamps: a wetland ecosystem where trees & vines grow

• occur in low lying areas & beside slow-moving rivers

• are flooded only part of the year depending on rainfall

• plants & animals found there: willow trees, bald cypress, water tupelos, oaks, elms, poison ivy, Spanish moss, water lilies, fish, snakes, birds

Saltwater Ecosystems• Saltwater is high in

density and sinks to the bottom of oceans, leaving freshwater on top.

• Largest in the world are the 5 oceans

• Estuaries, coral reefs, algae producing

River Delta• A delta is a

landform where the mouth of a river flows into an ocean, sea, desert, estuary or lake

• Sediment carried by the river and deposited as the water current endsNile River Delta

Watershed

• the region of land whose water drains into a specified body of water

• A drainage basin such as dog river which gets the end results of streams around Mobile county

Other Terms• Tributary- a stream that flows into a lake or larger

stream• Load- materials carried by a stream• Sediment-eroded soil or material• Erosion – the process where soil is transported or

removed• Deposition – is the process where material lays to rest• Salinity- a measure of the amount of salt in a given

amount of liquid• Flora - all plant life occurring in an area or time period • Fauna -a typical collection of animals found in a

specific time or place, – Two Types of Plankton

• Zooplankton- the (small animal) consumers that feed on phytoplankton,

• Phytoplankton- microscopic organisms that float near the surface of the water; they make their own food like plants on land do

Other Marine Environments• River – bodies of flowing water

moving in one direction• Photosynthesis - is the process by

which plants, some bacteria, use the energy from sunlight to produce sugar,

• Oxbow Lake – a lake formed when a river changes its course and the source is diverted away.

• Wetlands – areas of standing water (swamp, marsh, everglades)